1. Field of the Invention
This invention relates to the production of meltspun filaments of synthetic organic polymer. In particular, the invention concerns an improved cross-flow quenching apparatus that improves the decitex uniformity of the filaments.
2. Description of the Prior Art
Apparatus for cross-flow quenching of melt-spun filaments of synthetic organic polymer have long been known in the art, as for example, from U.S. Pat. No. 2,273,105, Heckert. In conventional apparatus of this type, melt-extruded filaments are supplied from spinneret orifices to an elongated chamber, called a "cross-flow chimney." Air is supplied to the chimney from a plenum through a plenum outlet that is substantially coextensive with one wall of the chimney. The plenum outlet usually contains means for reducing the turbulence in the air supplied to the chimney. Among the known air turbulence reducing means are open cell foams, perforated plates, screens, and the like which fit across the entire cross-section of the plenum outlet. Within the chimney the air flows from the plenum outlet through and around the filament array in substantially straight line paths that are substantially perpendicular to the paths of the filaments.
Although the known cross-flow quenching methods have been used extensively in the commercial production of melt-spun synthetic organic polymer filaments, yarns made from these filaments still have shortcomings in dtex uniformity along their length, especially when the filaments are of low dtex (e.g., less than 8, and especially when less than 5). Such nonuniformities lead to difficulties in subsequent operations such as dyeing and draw texturing. Thus, the purpose of this invention is to provide an improved apparatus that will increase the decitex uniformity of the melt-spun filaments.